"N_Cook" wrote in message
...
Gareth Magennis wrote in message
...

"N_Cook" wrote in message
...
Its confused because V3 splitter driver is physically on the op pcb,
but
all
3x .3 amp heater valves (6.3V setting) are in parallel for .9 amp total
at
node ( 6V or 6V1) and then in series with the 4 output valves, each at
.9
amp so in effect current-wise 5x .9 amp in series and 5 x 6.3V supply



Maybe that's so they can use Mickey Mouse connectors/PCB traces at 1 amp
capacity rather than have to hand wire proper heavy duty wires.
Whatever, it doesn't seem to work very well.

Makes a bit more sense now though, cheers.


Gareth.



So anyone live swapping V1,2 or3 will get too much power to the heaters on
the remainder . Or with heater failure in one triode may lead to a cascade
of failures assuming the mate of the first failed one would be similarly
disstressed.




Yep, I saw one 12AX7 glow far brighter than it should have done after
pulling another, which is why I warned you to be careful!



Gareth.